Cementing shoe for well casing



J. E. HALL Filed June 21, 1946 CEIMEbJTINQ-l SHOE FOR WELL. CASING Aug. 12,1952

Patented Aug. 12, 1952 CEMENING SHOE FOR WELL CASING Jesse E. Hall, Weatherford, Tex., assgnor of ten per cent to Parker Industrial Products, Inc., Weatherford, Tex., a corporation of Texas Application June 21, 1946, Serial No. 678,297

9 Claims. 1

This invention relates toV improvements in a casing shoe and refers more particularly to the tting employed at the bottom of a casing in oil and gas wells. Its principal use is during the cementing operation, but it remains attached to the casing after the well is brought under production. y

Inventive novelty resides primarily in the construction of the shoe which provides a sleeve valve arrangement affording maximum sized openings for the discharge of the cement mix from the casing and eliminates metal parts within the shoe which produce diiculties when it is desired to drill an additional hole below the shoe.

In cementing an oil or gas well which has been drilled to the desired depth, before the casing is run a cementing shoe is attached to the bottom of its lower section. After the casing has been set and mud circulation established, a charge of cement is introduced at the casing head in an amount sufcient to ll the annular space between the casing and well bore to a desired height. A cement plug is inserted in the casing behind the cement charge and the cement mix forced from the bottom of the casing by pressure applied behind the plug with mud fluid.

Heretofore cement shoes commonly used have had a ball valve located in a cage positioned centrally of the shoe. The ball valve prevents return of cement iiuid into the casing after it has been discharged. The discharge openings in the shoe through which cement mix ows from the casing usually consist oi a plurality of radial holes communicating with a central duct running longitudinally of the shoe. The principal objection to` this type of cementing shoe is the restriction .which itaiords to the passage of cement fluid from the casing to the annular space between the casing and well bore. Any delay whatsoever that can be avoided in the placing of the cement charge is exceedingly important to the success of the cementing operation.

An object. then,of the present invention is to provide maximum sized openings in the wall of the shoe which permit rapid egress of the cement from the casing.

Another object is the elimination of metal parts within the central portion of the shoe which vproduce difficulties in subsequent drilling operations.

A further object is to provide a valve mechanism within the shoe which is less easily blown out of the shoe body at the heavy pressure employed than is the ball valve construction now in common use.

Other and further objects will appearfrom the following description.

In the accompanying drawings which formv a part of the instant specification and are to be read in conjunction therewith, and in which like reference numerals indicate like parts in the various views,

Fig. 1 is a central section of a cementingsho'e embodyingA the invention, and

Fig. 2 is a view taken along the line 2-2 in Fig. 1 in the direction of the arrows.

Referring to the drawing, at I0 is shown Vthe lower end of the bottom section of a casing. The casing is threaded to receive the nipple I I. Machined in the lower end of the nipple is al bevelled seat IIa. The nipple is externally threaded at its lower end and screwed to these threads is the upper end of the shoe body I2. The bottom of the shoe terminates in the bevelled end IZa. Centrally located and cut through the peripheral wall' of the shoe are a plurality of openings or ports I3. The inner surface of the shoe at its lower end is grooved as shown at I2b to retain the bull nose guide I4. This guide is molded into the body' and is formed either of plastic, cement, or other easily drllable material. The guide has a central longitudinal duct I5 extending through its body from top to bottom.

Above the grooves I2b and within theh shoe body is formed a vertical rim I2C and behind this rim is an annular ledge on which is supported coil spring I6. The rim I2C is notched at intervals as indicated at Il.

Within the shoe body and supported upon coil spring I6 is a metal sleeve I8. Into the central cavity of the sleeve is molded a solid plug I9 of plastic, cement or other easily drillable material. 'The inner surface of the sleeve is preferably grooved to prevent the plug from being easily extruded by pressures imposed by the cement and mud fluid. The upper end of sleeve I8 isY bevelled to t and form a pressure tight seal against bevelled seat IIa of nipple II. On theouter periphery of the sleeve and running longitudinally thereof are valleys, depressions, or concaves vIlla arranged about the circumference of the sleeve and forming ducts which by-pass the valve.

It is contemplated that the area of the ports I3 in the shoe body shall be at least as great as the cross sectional area of the casing to afford maximum sized openings in the shoe facilitating rapid discharge of the cement mix therefrom.

In operation, after the casing has been set with the shoe attached, mud fluid `circulation is commenced. The mud is discharged from the bottom.l

3 of the casing through ports I3 by depression of the sleeve I8 against the force of compression spring I6. When the sleeve valve is depressed the seal at the bevelled seat I Ia is broken, permitting passage of uid through ducts Ia along the outside of the valve into the notches I1 which are in alignment with the ducts. In this manner, immediately the valve is unseated and throughout the period it remains unseated, a portion of the fluid Icy-passes the valve through grooves ISa and is discharged through the central duct IY through the bottom of the shoe. When the valve has been depressed sufficiently to open ports I3 the greater part of the fluid is discharged through these larger sized openings.

Thus it will be seen that first the mud fluid is discharged from the shoe in a cementing operation, then the cement mix follows and israpidly forced through the ports I3 of the shoe into the space between the casing and well bore. Following the charge of cement mix is a cementing plug which drives the fluid volume of cement mix out of -the casing. Pressure is applied behind the cementing plug by drilling fluid at the casing head. The cementing plug is stopped just above the shoe when the cementing operation is completed.

Arriva1of the plug at its destination is indicated by rapid rise of pressure at the casing head and at this time the pumps which supply the well uid are stopped. Pressure is now gradually relieved at the casing head. The weight of the column of cement surrounding the casing which is in communication with the bottom of the sleeve valve through duct I5, and aided by coil spring I6, returns the valve to its seat Ila. The column of cement is held by the valve for a suflicient period of time to set where it has been placed around the casing.

After the cement is set, the well is ready to produce when the casing has been perforated at the producing formation or by drilling a deeper hole through the shoe.

From the foregoing it will be seen that the invention is one well adapted to attain the ends and objects herein set forth together with other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter hereinv set forth or shown in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

AHaving thus described my invention, I claim:

1. A cementing shoe of the character described comprising a tubular body member attached to the bottom of the casing, a piston-like plug member axially movable within said body member and having a close sliding iit with the bore of said body member, upper and lower stops for the plug member limiting its axial travel, spring means urging said plug member upwardly, ports in the wall of the body member so located as to be covered and closed by said plug member when same is in its uppermost position, but uncovered and open when the plug member is in its lowermost position, a port in said body member disposed below the plug memberwhen same is in said lowermost position, and means within one 4 of said members providing an open passageway between said last port and the space above the plug member when the latter is in its lowermost position.

2. A cementing shoe of the character described, comprising a tubular body member attached to the bottom of the casing, a piston-like plug member axially movable within said body member and having a close sliding fit with the bore of said 'body member, upper and lower stops for the plug member limiting its axial travel, spring means urging said plug member upwardly, ports in the wall of the body member so located as to be covered and closed by said plug member when same is in its uppermost position but uncovered and open when the plug member is in its lowermost position, a port in said body member disposed below the plug when same is in said lowermost position, means within one of said members providing an open passageway between said lastv port and the space above the plug member when the latter is in its lowermost position, and valve means comprising cooperating elements on said plug member and body member operative to close said passageway when said plug member is in its uppermost position.

3. A cementing shoe of the character described, comprising a tubular member attached to the bottom of the casing, a piston-like plug member axially movable within said tubular member and having a close sliding t with the bore of said tubular member, upper and lower stops for the plug member limiting its axial travel, spring means urging the plug member upwardly, ports in the wall of said tubular member so located as to be covered and closed by the plug member when same is in its uppermost position but uncovered and open when the plug member is in its lowermost position, said tubular member con- Y structed and arranged to provide a cavity below fl. A cementing shoe of the character described,

comprising a tubular member attached to the bottom of the casing, a piston-like plug member axially movable within said tubular member and having a close sliding fit with the bore of said tubular member, upper and lower stops for the plug member limiting its axial travel, spring means urging the plug member upwardly, ports in the wall of said tubular member so located as to be covered and closed by the plug member when same is in its uppermost position but uncovered and open when the plug member is in its lowermost position, said tubular memberconstructed and arranged to provide a cavity below said plug when same is in its lowermost position and having a port connecting said cavity with the space outside the tubular member, longitudinal grooves in one of said members confronting the other member, said. grooves forming uid passageways connecting said cavity with the space above said plug member when same is in its lowermost position, and valve means comprising c0- operating elements on said plug member and tubular member operative to close said passageways iwhen the plug member is in its uppermost posiion. 5. A cementing shoe of the character described,

comprising a tubular member attached to the bottom of the casing, a piston-like plug member axially movable within the tubular member and having a close sliding t with the bore of said tubular member. upper and lower stops for the plug member limiting its axial movement, spring means urging the plug member upwardly, a plurality of circumferentially spaced ports in the wall of said tubular member, said ports so located as to be covered and closed by the plug member when same is in its uppermost position but uncovered and open when the plug member is in its lowermost position, said tubular member constructed and arranged to provide ya cavity below said plug when same is in said lowermost position and having a port connecting said cavity with the space outside the tubular member, and a plurality of circumferentially spaced longitudinal grooves in one of said members confronting the other member, said grooves staggered circumferentially relative said rst ports and forming iiuid passageways connecting said cavity with the space above said plug member when same is in its lowermost position.

6. A cementing shoe of the character described, comprising a tubular shell member xedly secured to the bottom of the casing, a sleeve member within the tubular shell member and slidably supported by the interior walls thereof, upper and lower stops for the sleeve member limiting its axial travel in the shell member, spring means urging the sleeve member upwardly, ports in the wall of said shell member so located as to be covered and closed by said sleeve member when same is in its uppermost position but uncovered and open when the sleeve member is in its lowermost position, a plug of easily drillable material closing the bore of the sleeve member and secured to the sleeve member for movement therewith, a nose of easily drillable material secured to the lower end of the tubular shell member, said nose having a port therein, and means within one of said members providing an open passageway between said last port and the space above said plug when the sleeve member is in its lowermost position.

7. A cementing shoe of the character described, comprising a tubular shell member iixedly secured to the bottom of the casing, a sleeve member within the tubular shell member and slidably supported by the interior walls thereof, upper and lower stops for the sleeve member limiting its axial travel in the shell member, spring means urging said sleeve member upwardly, ports in the wall of said shell member so located as to be covered and closed by said sleeve member when same is in its uppermost position but uncovered and open when the sleeve member is in its lowermost position, a plug of easily drillable material closing the bore of the sleeve member and secured to the sleeve member for movement therewith, a nose of easily drillable material secured to the lower end of the tubular shell member, said nose having a port therein, means within one of said members providing an open passageway between said last port and the space above said plug when the sleeve member is in its lowermost position, and valve means comprising cowhen the sleeve member is in its uppermost position.

8. A cementing shoe of the character described, comprising a tubular member xedly secured to the bottom of the casing, a sleeve member within the tubular member and slidably supported by the interior walls thereof, upper and lower stops for the sleeve member limiting its axial travel in said tubular member, spring means urging said sleeve member upwardly, ports in the wall of the tubular member so located as to be covered and closed by said sleeve member when same is in its uppermost position but uncovered and open when the sleeve is in its lowermost position, a plug of easily drillable material closing the bore of the sleeve member and secured to the sleeve member for movement therewith, a nose of easily drillable material secured to the lower end of the tubular member, said nose spaced below the lowermost position of said plug to provide a cavity between said nose and the plug when the latter is in its lowermost position, a port in the nose connecting said cavity with the space outside the nose, and longitudinal grooves in one of said members confronting the other member, said grooves forming fluid passageways connecting said cavity with the space above said plug member when same is in its lowermost position.

9. A cementing shoe of the character described, comprising a tubular member xedly secured to the bottom of the casing, a sleeve member within the tubular member and slidably supported by the interior walls thereof, upper and lower stops for the sleeve member limiting its axial travel in the tubular member, spring means urging said sleeve member upwardly, a plurality of circumferentially spaced ports in the wall of said tubular member, said ports so located as to be covered and closed by said sleeve member when same is in its uppermost position but uncovered and open when the sleeve member is in its lowermost position, a plug of easily drillable material closing the bore of said sleeve member and secured to the sleeve member for movement therewith, a nose of easily drillable material secured to the lower end of the tubular shell, said nose spaced below the lowermost position of said plug to provide a cavity between said nose and plug when the latter is in its lowermost position, a port in the nose connecting said cavity with the space outside the nose, and a plurality of circumferentially spaced longitudinal grooves in one of said members confronting the other member. said grooves staggered circumferentially relative said first ports and forming fluid passageways connecting said cavity with the space above said plug member when same is in its lowermost position.

JESSE E. HALL.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,071,390 Crowell Feb. 23, 1937 2,071,392 Crowell Feb. 23, 1937 2,310,483 Wickersham Feb. 9, 1943 2,352,744 Stoddard July 4, 1944 2,393,457 Burnett Jan. 22, 1946 

